The present invention relates to a display of a vehicle, and more particularly to a method and apparatus for generating a vertical situational display of a vehicle.
One of the many functions of a vertical situational display or VSD is to produce an image of a flight path from a current position of a vehicle to a destination. For example, the operator uses the flight path as a reference for lateral (i.e., range) guidance and vertical (i.e., altitude) guidance. The flight path is generally comprised of climb segments and descent segments typically defined by waypoints that begin at an origin threshold and end at a destination threshold. The climb, enroute and descent segments form a flight plan or FPL and the flight plan is visually displayed on the vertical situational display as a vertical situational image.
Generally, the image of a flight plan is produced on a vertical profile display located at a lower portion of a multi-function display or MFD. An input interface allows the operator to input a flight plan and develop the vertical profile. A processing device coupled to the input receives the input from the operator and generates the vertical profile of climb and descent segments. The climb, enroute and descent segments of the flight plan are typically generated using the linear equation of Y=MX, where Y is the altitude (i.e., vertical distance), X is the range and M is the slope, which is the ratio of the altitude to the range (i.e., M (the slope)=Y (altitude) /X (range).
Vertical situational displays use a number of techniques to generate the climb and descent segments of the flight plan in response to an operator input. For example, when a flight crewmember alters the range (X), the vertical situational display maintains a fixed altitude (Y). Therefore, as the flight crewmember alters the range (X) of the vertical profile, the climb angle or descent angle also changes and the slope of the climb segment and/or descent segment varies.
The suggestion has been made to use a constant slope (M) technique to improve a display that uses the varying slope technique. In contrast to a varying slope technique as briefly described in the preceding paragraph, the constant slope technique maintains a substantially constant or constant slope with an alteration of the range (X) through a modification of the altitude (Y). While the use of a constant slope technique significantly reduces the appearance on a display that the slope of the climb segment and/or descent segment varies with the alteration of the range (X), the use of a constant slope technique to display the climb segments and/or descent segments of a vertical situational image on a vertical situational display can cause a number of less than desirable visual display effects. For example, the flight plan can compress on the vertical situation display viewing area and reduce the visual reference and effectiveness for the operator of a vehicle.
In view of the foregoing, it should be appreciated that it would be desirable to provide methods and apparatus for generating a vertical situational display of a vehicle with a substantially constant or constant slope technique. In addition, it should be appreciated that it would be desirable to provide methods and apparatus for generating a vertical situational display of a vehicle with a substantially constant or constant slope technique with a reduction in undesirable display effects, such as compression of the vertical situational image on the vertical situational display. Furthermore, additional desirable features will become apparent to one skilled in the art from the foregoing background of the invention and following detailed description of a preferred exemplary embodiment and appended claims.
An apparatus and method are provided for generating a vertical situational image of a vehicle. The apparatus for generating a vertical situational image of the vehicle is comprised of an input device configured to receive flight plan data of the vehicle and a situational display configured to produce the vertical situational image from the flight plan data. The apparatus for generating a vertical situational image of the vehicle is further comprised of a processing device that is configured to receive the flight plan data from the input device, generate a first segment having a first slope in a first viewable range for the vertical situational image from the flight plan data and determine the first segment in a second viewable range of the vertical situational image. The processing device of the apparatus for generating a vertical situational image of the vehicle is further configured to modify the second viewable range to substantially maintain the first slope of the first segment if a viewable altitude of the vertical situational image is greater than an altitude threshold.